Improper Handling of Highly Compressed Data (Data Amplification) Affecting org.asynchttpclient:async-http-client package, versions [,2.16.1)[3.0.0.Beta1,3.0.12)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-ORGASYNCHTTPCLIENT-19963947
- published20 Sept 2026
- disclosed17 Sept 2026
- credithyperxpro
Introduced: 17 Sep 2026
NewCVE-2026-85721 (opens in a new tab)How to fix?
Upgrade org.asynchttpclient:async-http-client to version 2.16.1, 3.0.12 or higher.
Overview
org.asynchttpclient:async-http-client is a maven plugin for the Async Http Client (AHC) classes.
Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) through ChannelManager.newHttpContentDecompressor() in client/src/main/java/org/asynchttpclient/netty/channel/ChannelManager.java. An attacker can exhaust the client's heap and trigger an OutOfMemoryError by sending a small gzip, deflate, or snappy response that inflates without limit during automatic decompression. The vulnerable HTTP/1.1 path uses Netty's HttpContentDecompressor with the no-argument constructor, so a hostile or compromised server, or an attacker who can alter a response in transit, can make the client allocate decompressed data until memory is exhausted.
Workarounds
- Disable automatic decompression with
setEnableAutomaticDecompression(false)and decompress responses manually with your own size limit; this prevents the HTTP/1.1 client from inflating attacker-controlled bodies without bound. - On the 2.x line, remove the inflater handler through
httpAdditionalChannelInitializer; this prevents the client from installing the unbounded decompressor at all. - Run the client behind a proxy that caps response sizes; this limits how much compressed data can reach the client and reduces decompression-bomb impact.